title: Dormancy Associated Translation Inhibitor (DATIN/Rv0079) of Mycobacterium tuberculosis interacts with TLR2 and induces proinflammatory cytokine expression.
abstract: Mycobacterium tuberculosis, the cause of tuberculosis in humans, is present approximately in one third of the world's population, mostly in a dormant state. The proteins encoded by the dormancy survival regulon (DosR regulon) are mainly responsible for survival of the bacilli in a latent form. To maintain latency, mycobacteria orchestrate a balanced interplay of different cytokines secreted by immune cells during the granulomatous stage. The function of most of the DosR regulon proteins of M. tuberculosis is unknown. In this study, we have shown that one of the DosR regulon proteins, DATIN, encoded by the gene Rv0079, can stimulate macrophages and peripheral blood mononuclear cells (PBMC) to secrete important cytokines that may be significant in granuloma formation and its maintenance. The expression level of DATIN in Mycobacterium bovis BCG was found to be upregulated in pH stress and microaerobic conditions. Computational modeling, docking and simulation study suggested that DATIN might interact with TLR2. This was further confirmed through the interaction of recombinant DATIN with TLR2 expressed by HEK293 cells. When in vitro differentiated THP-1 cells were treated with recombinant DATIN, increased secretion of TNF-α, IL-1β and IL-8 was observed in a dose dependent manner. When differentiated THP-1 cells were infected with a modified BCG strain that overexpressed DATIN, augmented secretions of TNF-α, IL-1β and IL-8 were observed as compared to a reference BCG strain containing empty vector. Similarly, human PBMCs when infected with M. bovis BCG that overexpressed DATIN, upregulated secretion of proinflammatory cytokines IFN-γ, TNF-α, IL-1β and IL-8. The cytokine profiles dissected herein point to a possible role of DATIN in maintenance of latency with the help of the proinflammatory responses.
authors.affiliation: Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad, India.
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Kumar
authors.forename: Astrid
authors.initials: A
authors.lastname: Lewin
authors.forename: Pittu Sandhya
authors.initials: PS
authors.lastname: Rani
authors.forename: Insaf A
authors.initials: IA
authors.lastname: Qureshi
authors.forename: Savita
authors.initials: S
authors.lastname: Devi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Majid
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kamal
authors.forename: Stefanie
authors.initials: S
authors.lastname: Marek
authors.forename: Seyed E
authors.initials: SE
authors.lastname: Hasnain
authors.forename: Niyaz
authors.initials: N
authors.lastname: Ahmed
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002460:Cell Line; D057809:HEK293 Cells; D006801:Humans; D007249:Inflammation / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D009163:Mycobacterium bovis / Q000276:immunology / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D053583:Interleukin-1beta; D016209:Interleukin-8; C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma
keywords: Dormancy antigens; DosR regulon proteins; Mycobacterium tuberculosis; Proinflammatory cytokines; TLR2